Wrapper applying machine for newspapers



March 31, 1959 A. J. ZUERCHER WRAPPER APPLYINGYMACHINE FOR NEWSPAPERS 7Sheets-Sheet 1 Filed Jan. 23, 1957 A s WL LI m w a m w o z W A u a g 7 7o 4 2 M w 0 A? .0 -0

March 1959 A. J. ZUERCHER WRAPPER APPLYING MACHINE FOR NEWSPAPERS 7Sheets-Sheet 2 Filed Jan. 23, 1957 INVENTOR flaw/01w (1 205 mm @m/ '7?Away/v03 A F 0. E m,

March 31, 1959 ZUERCHER 2,879,636

WRAPPER APPLYING MACHINE FOR NEWSPAPERS Filed Jan. 23, 1957 7Sheets-Sheet s INVENTOR.

4 7 WAG-'73 7 Sheets-Sheet 4 INVENTOR. flaw/aw l 2015/9 /1 rray/yanMarch 31, 1959 A. J. ZUERCHER WRAPPER APPLYING MACHINE FOR NEWSPAPERSFil ed Jan. 23, 1957 March 31, 1959 A. J. ZUERCHER 2,879,636

' WRAPPER APPLYING MACHINE FOR NEWSPAPERS Filed Jan. 23, 1957 7Sheets-Sheet 5 Tic]- S.

l N V EN TOR. A/Yr/w/vy d. Z ua/vcms-e March 31, 1959 A RHER 2,879,636

WRAPPER APPLYING MACHINE FOR NEWSPAPERS Filed Jan. 23, 1957 7Sheets-sheaf; e

IN VEN TOR. flwrwowy d. Zuzecyq:

BY W

March 31, 1959 A. J. ZUERCHER 2,879,636

WRAPPER APPLYING MACHINE FOR NEWSPAPERS Filed Jan. 23, 1957 7Sheets-Sheet '7 Q :1. .E. 88 j \Ffi v INVENTOR. r A/YT/lO/VY U. ZusycmseBY 9- IN ,4 rrop/vays i edstatesPatefit O y WRAPPER APPLYING MACHINE FORNEWSPAPERS 9 Claims. (Cl. 53-7-53) The present invention relatesgenerally to newspaperhandling machines, and more particularly toapparatus adapted automatically tol apply top and bottom wrappers to astack of newspapers. prior to tying operations.

In modern newspaperplants, papers delivered from the press are bundledto facilitate truck delivery and bulk mailing. To form the bundles,papers discharged from the press are gathered into stacks which are thenplaced between top and bottom covers consisting of eight to sixteen-pagescrap sections, the covered stack being fed into a tying machine whereit is firmly bound by Wire. Normally, in standard mail rooms the paperstack will be made up of .fifty folded newspapers, twenty-five of whichwill be reversed to even the pile. The height of the stack will varyfrom day to day, depending, of course, on the size of the daily edition.The formation of stacks and the stack-covering operation have heretoforebeen carried out manually, several operators being required to transferpapers from the press to the tying machine in condition for bundling.

In view of the foregoing, it is the principal object of the invention toprovide a wrapper machine for newspapers adapted to apply top and bottomcovers to a newspaper stack automatically and at relatively high speed.A machine in accordance with the invention not only does away with theneed for the manual wrapping of newspaper stacks but is also capable ofincreasing the rate of wrapping to at least twice that of existingmanual techniques.

More particularly, it is an object of the invention to apply top andbottom covers to newspaper stacks prior to tying, while compensatingautomatically for difierent stack heights and spacings. An. importantadvantage of the machine is that it is self-adjusting in operation andneed not be altered to meet varying conditions of stack height orspacing in the course of operation.

Also an object of the invention is to provide an automatic wrappingmachine adapted to operate in conjunction with a counting-stackingmachine, thereby dispensing entirely with manual operations in thebundling of newspapers discharged from a'high speed press. Thus theinvention makes possible an automation system in which the printing andbundling of newspapers is carried out without manual intervention.

A significant feature of the invention resides in the use of a bundlestop, a deflector and an incomplete bundle-delivery device activated bysignals which are set up by the absence of a wrapper or the presence ofdoubles or more than two wrapper sections, whereby only properly wrappedstacks are fed to the tying machine. The bundle stop and deflector actto maintain the proper sequence of pre-addressed top wrappers whileoperating H 2,87%36 Paifenlzed Mar. 3

Briefly stated, in a preferred embodiment of a wrapping machine inaccordancewith the invention, a main conveyor'is provided to transport astack of newspaper through a wrapping station, a sheeter unit supplyinga bottom sheet to themain conveyor to engage the under-j side of thestack as it enters the station. Also provided at the station is a feederand applying' mechanism which supplies a top cover to the top side ofthe stack, the ap: plying mechanism being self-adjusting to the heightof the stack. A deflector mechanism at the exit of the sta-' tion isadapted to divert stacks from'the main'conveyor onto a reject conveyor,the deflector being activated only when an improperly wrapped stackleaves the station. Preceding the station. is agate mechanism whosetune-1 tion' is to block the passage'o'fstacks Jon the main con'- veyorin the, event the feeder mechanism fails. to pick up a top sheet fortransfer to the oncomingstack.

For a better understanding of the invention as Well as other objects andfurther features thereof, reference. is had to the following detaileddescription to be readi'n conjunction with the accompanying drawings,'wherein like components in the several views are represented by likereference numerals.

In the drawings: Fig. l is a ,plan view of a wrapping machine inaccordance with the invention.

Fig. 2 is a longitudinal section taken of the machine along the planeindicated by line 2+2 in Fig. 1.

Fig. 3 is a transverse section taken along the plane indicated by line33 in Fig. 2

Fig. 4 is an enlarged view showing a detail of machine illustrated inFig. 3. i

Fig. 5 is an enlarged front view of the wrapping station of the machine.

Fig. 6 is an enlarged side view of the wrapping station.

Fig. 7 is a detail showing the gate mechanisms for the machine.

Fig. 8 is a detail showing the double wrapper detection mechanism. v

Referring now to Figs. 1 to 4, the major components of the wrappermachine comprise an accelerating table, generally designated by numeral10, a main conveyor 11, a bottom she'eter unit 12, a wrapper-applyingstation 13 which includes a pre-cut top wrapper feeder 14, a bundlereject conveyor 15, and a deflector 16 'which acts to divert stacks fromthe main conveyoronto the reject conveyor 15 when the stacks areimproperly wrapped. The stack being fed along the conveyor into themachine is represented by stack 17. I v v p The details of theaccelerating roller table 10,- the main conveyor 11? and the bottoms'heeter unit 13 may either manually or automatically from acountingstacking machine, such asfis currently. manufactured by theCutler-Hammer Company, Rotatably mountedflon the table 10 are a seriesof rollers 18, chain-driven from a common drive shaft 19. The table ispivotally mounted. The function of the accelerating'roll table at theinput end of the machine is to impart an initial velocity to theincoming bundle and thereby to convey bundles from adjacent stackingmachinery to the wrapper-applyingfstation. The table pivots upwardly toafford access to roll stock spindles when replacing roll stock. i

The main conveyor system 11,"which is aligned with the rollers on theaccelerating table, includes two parallel rows of rollers 20 havingtheir axles journaled in end plates 21 which are secured to translatingroller chains 22 driven through a suitable gear system from a commonmotor 52. Thus if movement of the stack is arrested on the conveyor, therollers 20 will turn in a counterclockwise direction while whereby thestack will be maintained without disturbance at a fixed position despitecontinued movement of the chain. t v

Forward motion of a stack on the main conveyor trips a valve systemsupplying air to a cylinder-operated valve energizing a singlerevolution clutch which drives the botton'rwrapp'er sheeter 12. This isaccomplished by means of a trip wheel 23 which is .rotatably mounted ona pivoted latch member 24;,the latch being biased upv'vardly by a spring25, whereby the wheel is elevated somewhat above the level-of therollers 20 in themain conveyor to intercept the oncoming stack.

Thus when the stack rides on trip wheel 23, the latch 24'is rocked aboutits pivot point to release a pawl 26 which normally engages the hookofthe latch. Pawl 26 is linked to the plunger 27 ofja valve'28 in an aircylinder system having an air intakeduct 29, The air cylinder system,when tripped, acts to energize a single revolution clutch which may beof standard design (not shown). The' clu tch effects engagement betweena drive mechanisnrand a'sheeter cuttergcylinder 30 whereby the cylinthechain 22 moves forwardly,

. 4 the absence of a wrapper, as sensed by microswitch 44, will causedeflection of the stack onto the reject conveyor 11.

Rollers 47 on the reject conveyor are driven by belts 48 coupled to amotor-driven shaft 49, which shaft is also operatively coupled throughsuitable gear boxes to the common shaft 19 for the conveyors as well asto the other driven elements of the machine, such as the bottom sheeterunit. Shaft 49 is rotated by the common motor 52 which also drives asuitable vacuum pump 53 connected to the vacuum systems of the machine.

' The motor 52 also drives a bundle transfer conveyor v 1 54 constitutedby a pair of continuous belts 55 and 56,

supported along spring-loaded rollers and acting to transfer thebundles, after covers are applied thereto at the wrapping station 13, toan output conveyor 57 leading to a tying machine.

Pre-cut top wrappers 58, which may be individually addressed, are piledhorizontally on a table 59 adjacent der. makes one "full revolutionduring which a bottom cover is cut froma web and, spotted on theunderside of the'newspaper stack, The [manner in which this is carriedoutwill now be explained.

A web 31 of wrapper material, such aslcraft paper, is drawn from a reel32, the web passing under. adancer roll 33' mounted on the end of an arm34. pivotally supported at an eccentric point on the reel '32, the armbeing springloaded'to'hold the web under tension. 1 Correct tension pnthe webds maintained by a hand brake 35' which is actuatedin-accbrdanc'e with the angular position of the dancer roll relative toth'ereel.

The web 31'drawn from the reel 32 passes under the dancer. roll 33audovera metering" roller 40, the-web then going under the cuttercylinder and passing upwardlythrough guides 36 where it is driven by apair of spotting rolls 37 onto the conveyor rollers of the wrapper unit.3

The" sheeter cutter action is efiect'ed by a cutting rule 38, radiallymounted on the cutter cylinder 30 and projecting outwardly therefrom.-The'rule bears against a cylindrical toolsteel platen 39, the cuttercylinder and platen being supportedfor rotation insuitable bearings.Thus in'the course'of .one revolution, when the cutting rule' 38 engagesth'e 'surface of the platen the web31 is severed to proyide the bottomcoverfor the stack.

jfThe meteringfroller. 40 is undercut to provide a circurnterential g'roove 40d. Riding on ,the metering roller 40 1s a microswi'tch wheel41;mounted on theend' of a pivoted actuator" 'rin42 which cooperateswith the operat ing pin43 of -amicroswitch"element34, such'that shouldthe paperweb tear or, the stock be depleted before completion ofa run,the switchwill-close'acircuit to an alarm and cause operation of thedeflector 16. The manner in which this is carried out is 'as follows:The absence of paper on the metering roller due to a rupture in theweb Ior the depletion of stock will permit [the'microswitch wheel 41 to fallinto groove 4tla, thereby dropping actuator arm Alto release piri'.43,the release of the pin operating microswitch144. {The operation of themicroswitch closes a circuit in the control mechanism 46 for thedeflector 16.

The control mechanism 46, represented in block form 'in' Fig. 1, maybeconstituted by an air cylinder operated by a'solenoid valve under thecontrol of the microswitch the wrapper station 13. The top wrappers aretransported by a feeder mechanism 60, including sucker ele ments 61, tospotting rollers 62 and 63. The sucker elements attach .to the leadingedge of the wrapper, the top wrappers being maintained at a properelevation for'the suckers by a-self-compensating teed action. As thebundles move down the main conveyor 11 they acti-. vate a tripper device90 whose design may be similar to that of trip mechanism 23, thetripper'device acting to e'nergize'a' single revolution clutch for thetop wrapper feederrnechanism 60, whereby the feeder supplies one topwrapper for each bundle fed into the wrapper station.

At the wrapper station there is arranged an applier mechanismconstituted by a pair of applierarms each formed by an upper armcomponent 64, pivotally joined at an elbow 65 to a lower arm component66; The lower arm movement is restricted by a suitable'guide blockslidable within vertical tracks 67. Movement of the applier arms isetfected by a crank 68 connected to the upper extremity of the top armcomponents and pivotally connected to the piston 70 of an air cylinder69. The arrangement is such that when the cylinder piston 70 isprojected outwardly the applier arms are retracted to assume theposition shown in dotted lines in Fig. 2 where the elbow of the armsisraised within the upper hood 71. When'the piston is'drawn inwardlyinto the cylinder, the applier arms are extended downwardly in themanner shown in Fig; 1 so as to apply the top wrapper to the stack ofnewspapers.

As shown separately, in Figs. 5 and 6, the pre-cut top wrapper takenfrom pile 58 completes its" travel beneath theretr'actedappliermechanism, powered by rubber tires on "rolls and surface contactwith overhead belts 72, until the leading edge of the wrapper makescontact with adjustable stops 73, whereupon the wrapper stops and thebelts slip overhead.

. After the wrapper stops, the upper components 64 of the applier armare lowered by air cylinder 69, thereby causing a pair of spaced earns74, which are attached to the lower arm components and which areinitially in contact with the roller a at the end of lever 75, to pushlever 75 in the clockwise direction as the cams move downwardly, theroller 75a then swinging free of the 44. Alternatively, an electricmotorsystem may be used under the, control of the microswitch.

Deflector 16 acts tode tour a bundle lacking a bottom wrapper onto thereject conveyor 15. This conveyor may' consist of powered taperedrollers 47 mounted along a curved path leading'to a storage areawhere'manual 'corrections can 'be made before re-routing of the bundlesback to the input end of the wrapping machine. [Thup cams. Lever 75 isconnected to a shaft 75!; from which extend a pair of linkage arms 750whose ends are coupled by rollers to a bottom plate 76. When lever 75 iscaused by the lowering of the applier arms to swing in thecounterclockwise direction, the linkage arms act to-pull back the bottomplate 76 and thereby provide clearance for downward travel of theapplier mechanism.

Continued downward travel of the applier arms causes a trip 91 mountedon a gripper mechanism 77 straddled between the lower arm components tostrike a latch 78,

which action causes the gripper elements 79 to grasp the leading" edgeofthe wrapper. Grippers 79 are constituted by curved fingers *which are:pivoted on a shaft 79a and are adapted -to swing in the clockwise;direction against a seat 79b, the wrapper edge being clamped be tweenthe fingers and the seat. The applier arms, carry ing the top wrapperproceed downwardly, guided by tracks 67 until the rollers 80 on thegripper mechanism makes contact with the oncoming bundle adjacent theleading edge of the bundle. r

Contact between the rollers 80 andthe bundle triggers the grippers openand releases the wrapper.. This .is accomplished by a linkage mechanism(not. shown) which is caused to rotate shaft 79a. in a counterclockwisedirection. to remove the gripper fingers 79 from. the seat, this actionoccurring when the rollers 80 contact: the top of the bundle.-

To prevent excessive pressure between. the applier mechanism and thebundle, a relief valve (not shown.) is introduced in the down side ofthe air. cylinder 69 such that when a set pressure is exceeded airis.forced into the up side of the cylinder, thereby placing the appliermechanism in a state of equilibrium The.- balance is upset after apredetermined interval after which the down side of the cylinder isexhausted and pressure is supplied to the up side. Near the end'of theapplier return stroke, the cams 74 again contact roller 75a on lever 75to swing the lever clockwise and thereby to close .the bottom plate 76,which plate serves -tosupport the incoming top wrapper...

When the wrapper-applying machine is running in con junction withprogrammed stacking, pre-cut and pre. addressed top wrappers will beapplied in the same sequence as the bundles are fed in. Should the topwrapper feeder fail to supply a wrapper to the applier mocha nism, apneumatically operated gate 81 which. is disposed in advance of thetripper device 90 on the. main conveyor, as shown separately in Fig. 7,will obstruct the forward motion of the bundle, allowing the feeder torecycle until such time as a wrapper is in its proper position or anincoming bundle trips roller 23. In the latter case, the deflector 16will be activated, the gate opened, and all subsequent bundles shuntedonto the reject conveyor 15. If the wrapper is spotted in its properposition, the gate opens and a bundle with top and bottom wrappers areconveyed to the tying machine.

Missing top wrappers are detected to operate the gate or the deflector,the detection being made in connection with the suction system in thetop wrapper feeder mechanism 60. Should the sucker elements 61 remainuncovered thereby indicating the absence of a wrapper, air pressure isdirected to a valve arrangement to operate an air cylinder 82 which islinked to the gate 81 and which acts to raise the gate to obstruct theoncoming bundle. On the other hand, if the time at which the suckerelement is found to be uncovered occurs when a signal is received fromthe valve of the trip mechanism 23, the deflector is operated ratherthan the gate. In other words, if the absence of atop wrapper is sensedat a time when the next oncoming stack has reached the trip mechanism23, to prevent collision the deflector is actuated rather than the gate.If the suckers pick up a wrapper, vacuum builds up and air is directedto reset the feeder, the trip and the deflector.

When a double wrapper or more than two wrappers is inserted between thespotting rollers 62 and 63, as shown in Fig. 8, the increased thicknesscauses a roller 83 mounted on a lever 84 to swing out about the shaft 85on which the spotting roller 62 is mounted, throwing the upper tip ofthe lever out of toggle with the roller 86 on the actuating arm 87 of avalve 88 which acts to operate the control mechanism for the deflector16, thereby diverting the bundle with the double wrapper to the rejectcon veyor. The deflector system includes a memory or delay mechanismwhich is arranged in response to the actuation of valve 88 to remainoperative to divert not only the stack containing the double wrapper butalso the subsequent stack, the feeder being momentarily arrested. Thedeflector is. thereafter opened provided a. wrapper has been fed to thespotting rolls by the suckers. A. similar mechanism, not shown, isarranged to actin response to triples or more, but in such case thefeeder is neutralized since manual attention is required.

In summary, therefore, in the event a bundle is properly wrapped withtop and bottom covers, it will pass. through the wrapping station on themain conveyor for transfer to the. tying station.- But should a topwrapper not. be. picked up by the feeder mechanism, then the gate. willbe raised to obstruct the passage of. the. bundle into the wrappingstation until such time. as. a. wrappersis positioned by the feedermechanism- And should the missing; wrapper be. detected after thebundle'has passed the gateposts tion, then the deflector will operate inresponse to a trip: mechanism to divert the bundle to the reject orincomplete conveyor. Where a double. wrapper is picked up, the.deflector will operate to divert the double wrapped bundle as well asthe next bundle, and the feeder mechanism. will be arrested for onecycle. Similarly, should a bottom wrapper not be supplied to the wrapperstation, the de flector will operate to detour the improperly wrappedbundle. Should a greater number of wrappers be picked up, the deflectorwill operate to divert all. incoming bundles and the feeder neutralizeduntil manual correction is made.

While there has been shown what is. considered'to be a preferredembodiment of the invention, itwillbe manifest that many changes andmodifications may be made therein without departing from the essentialspirit of the invention. For example, in place of a feeder mechanism forpre-cut top wrappers, the mechanism may be adapted to operate inconjunction with wrappers cut from a continu-- ous web, in the mannerdisclosed herein in connection with the bottom wrappers. It is intended,therefore, in the; annexed claims to cover all such changes andmodificae tions as fall within the true scope of the invention.

What is claimed is:

l. A newspaper wrapping machine comprising awrapping station, a mainconveyor to transport a stack of news paper into and out of saidstation, meansto supply a sheet to said conveyor to engage the undersideof said stack. as. it enters the station, means at said station tosupply atop sheet to the top side of said stack, a reject conveyordiverging from said main conveyor, a deflector mechanism at the exit ofsaid station adapted to divert stacks from said main conveyor onto saidreject conveyor, and means to activate said deflector to detour a stackonto said reject conveyor when the stack leaving said station isimproperly wrapped.

2. A newspaper wrapping machine comprising a wrapping station, a mainconveyor to transport a stack of newspaper into and out of said station,means to supply a sheet to said conveyor to engage the underside of saidstack as it enters the station, a feeder and applier mechanism at saidstation to supply a top sheet to the top side of said stack, a rejectconveyor diverging from said main conveyor, a deflector mechanism at theexit of said station adapted to divert stacks from said main conveyoronto said reject conveyor, and means to activate said deflector todetour a stack onto said reject conveyor when the stack leaving saidstation is improperly wrapped.

3. A newspaper wrapping machine comprising a wrapping station, a mainconveyor to transport a stack of newspaper into and out of said station,means to supply a sheet to said conveyor to engage the underside of saidstack as it enters the station, a feeder and applier mcehanism at saidstation to supply a top sheet to the top side of said stack, a rejectconveyor diverging from said main conveyor, a deflector mechanism at theexit of said station adapted to divert stacks from said main conveyoronto said reject conveyor, and means to activate said deflector todetour a stack onto said reject conveyor when the stack leaving saidstation is improperly wrapped, a gating device preagsaoijeae cedingitheentrance .to said station on said main conveyor and responsive when saidfeeder mechanism fails. to pick up "atop sheet to obstruct the passageof stacks on said main conveyor.

' :4. A newspaper wrapping machine comprising a wrapping station, a mainconveyor to transport a stack of newspapers into and out of saidstation, a bottomsheeter unit to supply individual sheets to saidconveyor to engage. the underside of said stack as it enters thestation, afeederandapplier mechanism at said station to supply a topsheet to the top side of said stack, a reject conveyor diverging fromsaid main conveyor, a deflector mechanism at the exit of said stationadapted to detour stacks from said main conveyor onto said rejectconveyor, and means responsive to the failure of said bottom sheeter tosupply asheet to activate said deflector.

-5. A newspaper wrapping machine comprising a wrappingzstation, a mainconveyor to transport a stack of newspapers into and out of saidstation, a bottom sheeter unit to supply individual sheets to saidconveyor to engage the underside of said stack as it enters the station,a feeder and: applying mechanism at said station to supply a top sheetto the topside of said stack, a reject conveyor diverging from said mainconveyor, a deflector mechanism at theiexit of' said station adapted todetour stacks from said main conveyor onto said reject conveyor, andmeans responsive to an operation of said feeder and applying mechanismin which more than one sheet is transported to activate said deflector.

'6. A newspaper wrapping machine comprising a wrapping station', a mainconveyor to transport a stack of newspapers into and out of said'station, a bottom sheeter unit to supply individual sheets to saidconveyor to engage the underside of said stack as it enters the station,a'feeder mechanism at said station to supply a top sheet to the topsideof said stack, a reject conveyor diverging from'said main conveyor, adeflector mechanism at the exit of said stationadapted to detour stacksfrom said main conveyor onto said reject conveyor, means responsive tothe failureof said bottom sheeter to supply a sheet .to activate saiddeflector, and means responsive to the failure of said feeder-mechanismto supply a top sheet to activate said deflector.

7. A newspaper wrapping machine comprising a wrapping station, a mainconveyor to transport a stack of newspapers into and out of saidstation, a bottom sheeter 8 unit tosupply individual sheets 'to saidconveyorj'to'engage the underside of said. stack as it enters thestation, a. feeder and applier mechanism at said station to supply a topsheet to the top side of said stack, a reject conveyor diverging fromsaid main conveyor, a deflector mechanism at the 'exit of said stationadapted to detour stacks from said main conveyor onto said rejectconveyor, means responsive to the failure of said bottom sheeter tosupply a sheet tolactivate said deflector, means responsive'tothefailure-of said feeder "mechanism to supply a top sheet toactivate said deflector, and means responsive to an operation ofsaidfeeder mechanism in which more than one sheet is transported to activatesaid deflector. 'r. 8. A-newspaper wrapping machine comprising awrapping station, a main conveyor to transport a stack of newspapersinto and out of said station, a bottom sheeter unit to supply individualsheets to said conveyor to engage the underside of said stack as itenters the station, a feeder and applying mechanism at said station tosupply a top sheet to the top side of said stack, a reject conveyordiverging from said main conveyor, a deflector mechanism at the;exit ofsaid station adapted to detour stacks fromsaid main conveyor onto saidreject conveyor, means responsive to the failure of said bottom sheeterto supply a sheet to activate said deflector, means responsive t'o-thefailure of said feeder mechanism to supply a top sheet to activate saiddeflector, means responsive to an operation of said feeder mechanism inwhich more than one sheet-is transported to activate said deflector, agating device on said main conveyor preceding the entrance to saidstation, and means responsive to the failure of. said feeder mechanismto pick up a top sheet to actuate said gating device and therebyobstruct the passage of stacks on said main conveyor. 9. A machine, as;set forth in claim 8, wherein said top sheet-.alpplying mechanismincludes arms for carrying a sheet onto the top of said'stack and meansresponsive to the pressure of said arms on said top of said stack toretract said arms when a predetermined pressure is' exceeded.

References Cited the file of this patent UNITED STATES PATENTS

